This invention relates generally to compact, electrically energizable door strike apparatus, and more particularly, to an improved mechanism wherein a solenoid is operable to control strike latch mechanism, and wherein a solenoid may have either of two different selected positions. In one position of the solenoid, the mechanism has a fail safe mode, wherein, if power to the solenoid fails, the bolt allows a door to be safely opened; and in the other selected position of the solenoid, the mechanism has a fail secure mode, wherein, if power to the solenoid fails, the bolt secures the door against opening.
There is need for electrically controlled strike bolts of simple, compact construction for securing doors against opening, and also for allowing door opening, in case of power failure. Previously, these two functions required two different strike devices, each device preventing only one of these functions. No way was known, to my knowledge, to embody the two functions in a single mechanism which could be simply adjusted to allow one or the other of such functions to be in effect.